The invention relates to footwear.
There are a wide variety of shoe constructions. One construction method, known as the Opanka construction method, includes hand-sewing an outsole of a shoe to an upper of the shoe along the entire outer periphery of the outsole. The Opanka construction method has typically been employed in constructing casual and sandal-type footwear. For this reason, producing a comfortable, soft-stepping shoe is an important quality for Opanka constructed footwear.
In a general aspect of the invention, a method for constructing footwear includes the following steps. An upper defining a volume for receiving a wearer""s foot is provided. A midsole having an inner surface, an outer surface opposite to the inner surface, and an upstanding sidewall around its periphery is also provided. The upper is then attached to the midsole by stitching a thread along a peripheral portion of the upper and the sidewall of the midsole. An outsole, having a walking surface and an attachment surface opposite to the walking surface is then attached to the outer surface of the midsole adjacent to the attachment surface of the outsole. The outer surface of the midsole is then attached to the attachment surface of the outsole.
Embodiments of the invention may include one or more of the following additional steps. A channel is formed in the upstanding sidewall of the midsole, the channel extending from a peripheral-edge of the midsole in a direction parallel to the plane of the inner surface of the midsole, the channel sized to receive the thread for stitching the upper to the midsole. The channel serves to help hide and protect the thread used to attach the upper of a shoe to its midsole, giving the shoe a better appearance and a longer life.
A cavity is formed in at least the forward portion of the inner surface of the midsole and resilient material is positioned within that cavity. The resilient material within the cavity acts to cushion a wearer""s foot and protects the wearer""s foot (or sock) from excessive wear while walking.
A cavity is provided in the outer surface of the midsole and cushiony material is provided within that cavity. Footwear having such a cavity filled with cushiony material, be it a boot, a sandal, or a casual shoe, gives a greater spring-like, cushiony, and more comfortable feel to the wearer of the shoes. The cushiony material is high density polyurethane or latex foam which produces a more comfortable shoe.
A cut-but is provided in the midsole and cushiony material is positioned and maintained within that cut-out. In certain embodiments, the cushiony material includes woven material which may be elastic and is maintained within the cut-out by being stitched to the midsole. Such embodiments provide levels of spring-like comfort to the wearers of these shoes. The cushiony material provided within the cut-outs may also be made of a high density polyurethane or latex form.
In yet other embodiments of the invention one or more of the following steps may be present. The midsole is molded to possess a roughened outer surface to facilitate adhesively bonding the outer surface of the midsole to the attachment surface of the outsole.
The outsole is made of a single unitary member. Such an outsole made of a single unitary member advantageously provides flexibility for designing the shoes.
In another aspect of the invention, footwear includes an upper which defines a volume for receiving a wearer""s foot; a midsole which has an inner surface, an outer surface opposite to the inner surface, and an upstanding sidewall around its periphery; stitching, which attaches the upper to the midsole along a peripheral portion of the upper and the sidewall of the midsole; and an outsole, which has a walking surface and an attachment surface opposite to the walking surface. The outer surface of the midsole is attached to the opposed surface of the outsole.
Embodiments of this invention may include one or more of the following additional features. A channel is formed in the upstanding sidewall of the midsole. The channel extends from a peripheral edge of the midsole in a direction parallel to the plane of the inner surface of the midsole. The channel is sized to receive a thread for stitching the upper to the midsole.
A cavity is formed in at least the forward portion of the inner surface of the midsole and is filled with resilient material to cushion a wearer""s foot while walking.
A cavity is formed in the outer surface of the midsole and contains cushiony material to give a greater spring-like, cushiony, and more comfortable feel to the shoe""s wearer. The cushiony material positioned within this cavity is made from a high density polyurethane or latex foam.
A cut-out in the midsole contains cushiony material including woven material which may also be elastic. Alternatively, the cushiony material is made from a high density polyurethane or latex foam. The cushiony material is secured within the cut-out by stitching the cushiony material to the midsole.
In yet other embodiments of the invention one or more of the following features may be present. The midsole is molded to have a roughened outer surface. The outsole is made of a single unitary member.
Footwear having the above arrangement advantageously uses a midsole to provide a flexible platform upon which different outsole styles and designs can be attached to a particular upper and midsole combination. Shoe manufacturers using this invention have greater flexibility in designing, creating, and assembling such shoes.
Other advantages of the above-described footwear and construction method include the ability to allow such shoes to be manufactured in separate stages or even at different locations. The invention also enables the construction of Opanka style shoes having an outsole made of any suitable outsole material e.g., rubber, TPR, PVC, EVA, etc.
Other advantages and features of the invention will be apparent from the following detailed description of presently preferred embodiments and from the claims.